An organic electroluminescence device (hereinafter, occasionally abbreviated as “organic EL device”) using an organic substance is expected to be used as a cost-friendly full-color display device (solid light-emitting device) with a large area and thus many developments thereof have been made. A general organic EL device includes an emitting layer and a pair of opposing electrodes between which the emitting layer is interposed. When an electric field is applied between the electrodes, electrons are injected from a cathode, while holes are injected from an anode. Subsequently, the electrons are recombined with the holes in the emitting layer to generate an excited state and energy generated when the excited state returns to a ground state is emitted in the form of light.
The performance of an organic EL device has been gradually improved by improving an organic-EL-device material. In particular, improvement in the color purity of a blue-emitting organic EL device (i.e., shortening of an emission wavelength) is considered as an important technique for improving the color reproducibility of a display.
Patent Literature 1 discloses that a fused aromatic hydrocarbon group having two amino groups as substituents is used as a dopant material.
Patent Literature 2 discloses a diaminopyrene dopant containing dibenzofuran and a combination of such a dopant material and an anthracene host material.
Patent Literature 3 discloses a diaminopyrene dopant having such a structure that a nitrogen atom is directly bonded to the 2-position or 4-position of each of dibenzofuran and dibenzothiophene.